Stone-girdling tool.



M. D. DREYFUS.

STONE GIRDLING TOOL.

APPLICATION man JAN. 25. I917.

1,244,716. Patented Oct. 30,1917.

3513 A attozwzu NITED, STAT S STONE-GIRDLING root.

. especially diamondsi The girdling of 'diamonds has heretofore been accomplished by hand-grinding, and the object of my invention is, as has been stated, to provide a tool to girdle or trim the peripheral edge of a stone by mechanical means whereby a great amount of time is saved and a more accurate circle is produced. My improved tool may,

' V of course, also be utilized for other purposes.

' I will .now proceed to describe my invention. in detail, the novel features of which I will point out in the appended. claims, reference being had to the accompanying'drawing, forming part hereof, wherein:

Figure 1 is a face view of my improved cutting tool illustrated as connected to a drill chuckj h I Fig. 2 is anenlarged cross-sectional view, the section being taken on a'line 2 -2 in Fig. 1;'

Fig. 3 I on a line '33 in said Fig. 1; Fig'. 4 is an enlarged vertical sectional fv-iew, thesection being taken on a line .inFigl'l; Fig. 5 is a perspective view of a modified form of my cutting tool;

Fig." 6 is an enlarged; sectional plan view, illustrating a cutting tool positioned to cut the rag ed or rough edge 0f stones encomp ssed t ereby; -I. a; i I i.

Fig. .7 is a sectional view of amodified is a similar view, the sectionbeing form of means to lock the adjusting spindle;

Fig. 8 is a sectional view illustrating the action of the grinders; and

Fig. 9 is a perspective view of another form of circular grinder.

As herein embodied, my invention comprises a frame or holder 1 carrying crossbars 2 and 3 which slidably retain the posts 4 and 5 which carry the grinding. tools 6 and 7. These tools are made of suitable hard metal, the grinding edges of which are pro:

PATENT. .f

1). DREYFUS, ornn'w 'ironKylvsY. f

Specification of Letters Patent.

Patented oeeso, "19171..

'Applicat ion filed January 25, 917. serialNo. 144,359.

vided with well-known diamond grinding compositions, such as diamond-duster the like, the manner of forming such grinding edges being. well-known in the .art; Each post 4: and 5 carries ablock 8 towhich its respective grinder is detachably secured by bolts 9. The upper end of each post 4; and 5 carriesa threaded projection 10 which-is engaged by a jam or lock-nut 11. .To ad= Just the posts t and 5, and consequently the grinders '6 and 7 ,1 Iv provide 'a rotatable spindle 12 carrying a'thumbwheel 13.?The

spindle '12 is oppositely threaded as shown,

the right-hand tlireadedportion engaging a threaded opening in the hubld of the post 4,

The left-handthreaded portion of the spine dle 12 engagesthe hub 14. of, thepost' 5. When the spindle is rotated, the grindersfi and 7 will be adjustedtowardor away from each-other according 'to the direction "of rotation. When adjusted'theposts4 and-'5 and their grinders will be locked .in the adjusted positionby the lock-nuts 11-. To ne1'.- I

mit the posts to be adj uisted longitudinally of the holder 1, or cross bars 2 and 3,1I'provlde' said cross-bars with slots'15 and .16,

respectively, "through which the said ;,ptst s pass. The" grinders consist or the shanks 6 and 7 a and the semi-cylindrical or; cage grinding portionsor members 15 and16 carried thereby. The shanks 6 and are formed preferably integral with the semicylindrical "portions" 1 5. .and'16 respec tively. Each portion 15* and 16 ispro- .vided 'witha grindingedge 17 to trimjor true upthe rough peripheral edge of a gem 19 (Fig. 8). .Thesemi-cylindrical or cage portions, whenarranged or adjusted for the .gem which they are to trim or true up, act asjg en erin d i e h gem other words, the'gemto be trued or ground' will "lay within" 5 the circle formed 1 by". the two semi-cylindrical ca e-portionsairbag-rind. e .H nc theeem W l not b l sh out of position to any harmful extent while the grinding edges are performing their function.

Instead of the semi-cylindrical cages and their grinding edges, I may employ, for some classes of work, straight grinders, indicated by 20 in Fig. 5, the grinding edge thereof being indicated by 21. I For soft stones or metal (indicated by 19*, Fig. 6) cutters such as (Wand '7 can be em- Instead of employing the a nrnuts 11,1011

the posts 4 and 5, I may mount a lock-nut 22 directly upon the spindle 12, as illustrated in Fig. 7. For stones of different sizes or diameters, I employ gri n ders 6 and Thav lng semi-cylindrical cages of suitable radius.

To accommodate stones of different diameters,uthe postsl and 5.; will be adjusted alongthe holder. WVhen an adjustmentis made, grinders. of suitable size will have to be applied to the posts l and .5.

The holder ,1 will be applied to a chuck 23 oi":al drill, or the like, and, while rotating, Will beied against the edge of the stone to be trued up; hencethe girdle edgeiof the stone will-be ground to anexact circleor approximately so. A stone'trued by ny in proved device will be more perfectly formed, atlessfcost, than could be accomplished by hand; If desirable micrometer scale indications 24: lcantbe applied to the holder .1 adj a cent the ladjustableposts land 5. i To girdle diamond brother hard stones, I may, employ a one-piece grinding. tool in- Adicatedby 2,5, Fig-9, which. can be held "by the. postsl and .5. To-atta'ch the grinde1i25,

the posts will be. moved, apart or, moved together, to engagethe shanks 26 .of the grinder .2 5; This forin; of grinder is desirable for hard stories, ,as there will be no tendency to spread while being fed against the stone. "The edge 27 of the-grinder 25 will, be the grinding edge, the cn-ttingor grinding. edges of these tools beingfn' ade of wellflknown', diamond grindingwconrpositions. Having nowdescribedmy rinaelltion, what i I" claim and desire to secureby LettersPatentis: V I

1, A grinding tool =COInprising-a holdeiga n plurality .of grinders adjustably: carried thereby, each grinder consisting. of a semipylindrical cage-portion, and a grinding edge. carried by. each rage-portion. ,2. rinding tool comprising-a holder, a spind le'rotatably supportedthereby and provyided withsright and left hand threads, a slid- .ablepost engaging the, lefthand threads of :the spindle, a second post engagingthe righta hand threads of, said spindle, inean torotate said-Yspindle'qmeans to lock the: posts in day of January,

adjusted positions, and grinders rcmovably secured to said posts.

3. A grinding ,tool consisting of a holder, cross-bars carried thereby and provided with slots, posts slidably engaging said slots,

'lIlGEIllS to slide said posts in said slots, means "tolbc'lbsaid posts when moved .to adesired pos t on, and grinders carried by said posts.

' 4. A grinding tool, consisting of a holderirame, a pair of OlOSS-bZLI'S carried thereby and I provided with slots, postspassing through and slidably engaging said slots, a threaded spindle engaging said posts, means to rotate. said spindle, and grinders carried by said posts.

5. A: grinding tool, consisting of a holder, cross-bars carried thereby and provided with slots, posts slidably. engaging said slots, a threaded :spindle'engaging said posts,

means ,to rotate said spindle,v grinders careach projection to bearagainst the, adjacent cross-bar andlock said posts againstmov'enient :after said posts have been adjusted];

- 7. A grinding tool, comprising a holder.- fra1ne, a rotatable threaded spind'lerarried thereby, grinders zadjustably connected to said spindle, and a jam-nut to lock said spindle against rotation. v

8. A grinding tool for precious stones, consisting-of a curved cage having a grinding. edge at the lower end thereof, a d

shanks eXtending from said cage adapted to engagearotatable support. a p

9. A grlndlng tool for precious stones,

oo nprisinga plurality, of curved cages7ari ranged; to forina circle, each cage hayinga grinding edge at the lower end thereof; Signed. at New York city, ,Y., this 24 p H i DREYF-US. (Witness;

MAURICE Brook. 

